Prepare game updates and single-process PM2 deployment

deploy/nginx.conf.example

@@ -0,0 +1,48 @@
+# Install in an nginx http-context include (e.g. sites-enabled).
+# Replace game.example.com and certificate paths before enabling.
+map $http_upgrade $dragon_ball_connection {
+    default upgrade;
+    '' close;
+}
+limit_req_zone $binary_remote_addr zone=dragon_ball_signal:10m rate=10r/s;
+
+server {
+    listen 80;
+    server_name game.example.com;
+    return 301 https://game.example.com$request_uri;
+}
+
+server {
+    listen 443 ssl;
+    server_name game.example.com;
+    ssl_certificate /etc/letsencrypt/live/game.example.com/fullchain.pem;
+    ssl_certificate_key /etc/letsencrypt/live/game.example.com/privkey.pem;
+    ssl_protocols TLSv1.2 TLSv1.3;
+    client_max_body_size 16k;
+    access_log off;
+
+    location / {
+        proxy_pass http://127.0.0.1:2100;
+        proxy_http_version 1.1;
+        proxy_set_header Host $host;
+        # Internet-facing nginx on the app host; discard client-supplied forwarding.
+        proxy_set_header X-Forwarded-For $remote_addr;
+        proxy_set_header X-Forwarded-Proto $scheme;
+        proxy_set_header Connection "";
+    }
+
+    location /socket.io/ {
+        limit_req zone=dragon_ball_signal burst=40 nodelay;
+        limit_req_status 429;
+        proxy_pass http://127.0.0.1:2100;
+        proxy_http_version 1.1;
+        proxy_set_header Host $host;
+        proxy_set_header X-Forwarded-For $remote_addr;
+        proxy_set_header X-Forwarded-Proto $scheme;
+        proxy_set_header Upgrade $http_upgrade;
+        proxy_set_header Connection $dragon_ball_connection;
+        proxy_read_timeout 75s;
+        proxy_send_timeout 75s;
+        proxy_buffering off;
+    }
+}